Enhanced hydrogen production rates in Microbial Electrolysis Cell using Biocatalyst

The energy consumption around the world has increased significantly and depleting reserves posing a major concern. The green energy sources are the need of the hour to counter the fuel scarcity and souring prices. Hydrogen production through a microbial electrolysis cell (MEC) is an effective and green technology. It is a bio-electrochemical system where microbial oxidation of organic feed at anode and reduction of protons to Hydrogen at cathode takes place. To derive hydrogen evolution reaction (HER) over the cathode, an external applied voltage of 0.2V is required which is very nominal in comparison to the voltage required for water electrolysis. In the present study, the reactor digestate derived biochar biocatalyst was evaluated for its impact in the process parameter enhancements. The bio-catalyzed membrane-less single chambered MEC (BC-SC-MEC) in a batch mode at an applied voltage of 0.8 V had resulted into higher COD removal efficiency and hydrogen production rates at 30 ± 2 °C (Fig.1). The COD removal of 78%, with Coulombic efficiency of 60% and cathodic hydrogen recovery of 52 % were reported in BC-SC-MEC, while SC-MEC resulted into COD removal of 72%, coulombic efficiency of 55% and cathodic hydrogen recovery of 48% were reported. These results support the claim of boosted hydrogen production in the bio-catalyzed MEC for enhanced energy recovery.